Background: Leakage of components from endodontic materials (EM) can occur in case of apical extrusion into the periapical tissue. Therefore, an important prerequisite, besides the mechanical properties of the EM, is a high biocompatibility. In the present study, we elucidated the genotoxic potential of EMs of different base composition by utilizing the -H2AX assay.
Methods: For investigation of the genotoxic potential of EM, supernatants of commercially available EM were prepared and dilutions were applied to human gingival fibroblasts. Non-toxic doses of EM were determined by cell viability assay. For the -H2AX assay, human gingival fibroblasts were incubated with predefined concentrations of the supernatants, which were found not to reduce cell viability. Hydrogen peroxide was utilized as positive control. Cells were fixed 1, 6 and 24 hours after addition of the supernatant to the medium, followed by immunostaining for -H2AX. For scoring of -H2AX foci, automated foci counting was performed in at least 80 cells per experiment and time point. The experiments were repeated at least twice.
Results: In contrast to hydrogen peroxide treated cells, no elevated -H2AX levels were detected in cells incubated with the EM supernatants.
Conclusions: Samples treated with EM supernatants showed no elevated levels of -H2AX foci, e.g., no genotoxicity. Therefore, all types of EM seem to meet the standard to be called a biocompatible dental material in terms of genotoxicity, and, therefore, the application seems safe.